From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Thu, 6 Jul 2017 16:17:14 +0200
Subject: KVM: mark memory slots as rcu
Patch-mainline: v4.13-rc1
Git-commit: a80cf7b5f4149753d5f19c872a47e66195b167d4
References: bsc#1077761
we access the memslots array via srcu. Mark it as such and
use the right access functions also for the freeing of
memory slots.
Found by sparse:
./include/linux/kvm_host.h:565:16: error: incompatible types in
comparison expression (different address spaces)
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
---
include/linux/kvm_host.h | 2 +-
virt/kvm/kvm_main.c | 6 ++++--
2 files changed, 5 insertions(+), 3 deletions(-)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -390,7 +390,7 @@
spinlock_t mmu_lock;
struct mutex slots_lock;
struct mm_struct *mm; /* userspace tied to this vm */
- struct kvm_memslots *memslots[KVM_ADDRESS_SPACE_NUM];
+ struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
/*
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -713,7 +713,8 @@
for (i = 0; i < KVM_NR_BUSES; i++)
kfree(rcu_access_pointer(kvm->buses[i]));
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
- kvm_free_memslots(kvm, kvm->memslots[i]);
+ kvm_free_memslots(kvm,
+ rcu_dereference_protected(kvm->memslots[i], 1));
kvm_arch_free_vm(kvm);
mmdrop(current->mm);
return ERR_PTR(r);
@@ -762,7 +763,8 @@
kvm_arch_destroy_vm(kvm);
kvm_destroy_devices(kvm);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
- kvm_free_memslots(kvm, kvm->memslots[i]);
+ kvm_free_memslots(kvm,
+ rcu_dereference_protected(kvm->memslots[i], 1));
cleanup_srcu_struct(&kvm->irq_srcu);
cleanup_srcu_struct(&kvm->srcu);
kvm_arch_free_vm(kvm);